Post navigation

About ACL Injuries

What is an ACL?

The anterior cruciate ligament (ACL) is one of four main ligaments in the knee joint. The ACL is a ligament in the center of the knee joint that connects the bottom of the thigh bone to the top of the shinbone and provides the knee with stability.

How does an ACL injury occur?

The ACL is commonly injured by a hit to the knee (contact) or when an athlete is stopping suddenly, pivoting, slowing down quickly after running or landing from a jump (non-contact). Athletes who tear their ACLs often hear a popping sound, accompanied by knee pain and instability.

Who is at risk?

Any athlete can be injured, but ACL injuries are more prevalent in those who participate in high demand sports that require pivoting and cutting movements or quick planting of the feet, such as soccer, lacrosse, hockey, basketball, football, skiing, volleyball, cheerleading and gymnastics.

The gender bias

Studies show that teenage female athletes are at higher risk of ACL injuries than teenage male athletes. Young women athletes are anywhere from two to 10 times more at risk of an ACL tear because of differences in biomechanics and body shape. Female hormones can also cause an increased looseness in ligaments, making girls more vulnerable to tears.

Why are ACL injuries on the rise?

The number of ACL injuries is skyrocketing – especially in young people. Nationally, nearly half a million injuries occur in the U.S. every year, and physicians in Philadelphia have reported a 400 percent increase in ACL tears in 10 years. The number of ACL patients seen by Midwest Orthopaedics at Rush (MOR) physicians has more than doubled in the last five years. Still, what concerns physicians the most is the increase in ACL injuries among athletes under 25 years of age. MOR noticed that the number of ACL patients in this age group tripled over the past five years.

Physicians agree that the rise in ACL injuries has to do with stiff competition and year-round play of one sport, without breaks or resting between seasons. The numbers are also high because more girls are playing competitive sports.